import math
from math import pow

x = "abc"
n = "de"

num1 = x+n  # 连按字符串x和n

num2 = x*3  # 复制字符串x三次

num3 = x in n   # 判断字中x是否为n的子串

num4 = str(2)   # 检索字符串x中的第2个字符

num5 = x[0:3]   # 将字符x中1-3的内容切取下来

print(num1)
print(num2)
print(num3)
print(num4)
print(num5)
